gpu: nvgpu: Remove redundant locked variable

Queue locked variable holds entirely redundant information about the
queue status and having the variable causes a race between lock() and
unlock() functions. This patch removes the locked variable.

Bug 1495617

Change-Id: I05682bfe7a23acc77c2bfe405938ace7d2b3d081
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-on: http://git-master/r/393431
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Prashant Malani <pmalani@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 3 insertions, 17 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/pmu_gk20a.c b/drivers/gpu/nvgpu/gk20a/pmu_gk20a.c
index c4bfe527..e9e0c26f 100644
--- a/drivers/gpu/nvgpu/gk20a/pmu_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/pmu_gk20a.c
@@ -1270,15 +1270,10 @@ static int pmu_queue_lock(struct pmu_gk20a *pmu,
 
         if (PMU_IS_SW_COMMAND_QUEUE(queue->id)) {
                 mutex_lock(&queue->mutex);
-                queue->locked = true;
                 return 0;
         }
 
-        err = pmu_mutex_acquire(pmu, queue->mutex_id,
-                        &queue->mutex_lock);
-        if (err == 0)
-                queue->locked = true;
-
+        err = pmu_mutex_acquire(pmu, queue->mutex_id, &queue->mutex_lock);
         return err;
 }
 
@@ -1292,18 +1287,11 @@ static int pmu_queue_unlock(struct pmu_gk20a *pmu,
 
         if (PMU_IS_SW_COMMAND_QUEUE(queue->id)) {
                 mutex_unlock(&queue->mutex);
-                queue->locked = false;
                 return 0;
         }
 
-        if (queue->locked) {
-                err = pmu_mutex_release(pmu, queue->mutex_id,
-                                &queue->mutex_lock);
-                if (err == 0)
-                        queue->locked = false;
-        }
-
-        return 0;
+        err = pmu_mutex_release(pmu, queue->mutex_id, &queue->mutex_lock);
+        return err;
 }
 
 /* called by pmu_read_message, no lock */
@@ -1327,8 +1315,6 @@ static bool pmu_queue_has_room(struct pmu_gk20a *pmu,
         u32 head, tail, free;
         bool rewind = false;
 
-        BUG_ON(!queue->locked);
-
         size = ALIGN(size, QUEUE_ALIGNMENT);
 
         pmu_queue_head(pmu, queue, &head, QUEUE_GET);